Rotary shaft coupling



Original Filed May 20, 1942 I INVENTbR. BY zwnmss ovsmr Patented Aug.7., 1945 v 2,381,770 I ROTARYSHAFT COUPLING Charles F. Overly, EastCleveland, Ohio Original application May 20, 1942, Serial No. 443,743.Dividedand this application Novem- I ber 10, 1943, Serial-No. 509,953

4Claims. (01. 64-23) This invention relates to rotary shaft couplingsand is a divisional application of my'co-pending application, SenNo.443,743, for .fRotary power tool, filed May-20, 1942, now;Patent.No.2,375,.- 490, issued May 8, 1945. 1; 1

The, general object of. this: invention..is. the provision of a,practical and economic, rotary shaft coupling of a shaft and matingmember sleevedtogether and keyed to ,each other so that the "shaft andmating member fit, together without looseness andwith perfect freedom; w

A particular field of use for this type of coupling, although theinventionis not restricted to such a field, is the coupling of shaftsinsmall tools and small power tools in which the, coupled shafts mustrun quietly and smoothly without backlash between engaging parts withoutwear at the contacting surfaces and without deformation of the engagingparts.

This general object of the invention is attained by coupling a shaft andmating member by means of a, U-shaped key member dimensioned to fitoppositely arranged key slots in the outer peripheral'wall of the shaftand the inner peripheral wall of the mating member so that the webportion of the U-shaped key extends diametrically over the end face ofthe shaft.

Another object of the invention is the provision of a coupling forrotary shafts in which a shaft and mating member sleeved upon said shafteach are formed with diametrically opposed key ways and keyedtogether bya U-shaped key member, the leg portions of which are inserted in theopposed key ways of said shaft and mating member, and the web portion ofwhich is extended into said mating member in diametrical relation withrespect to said shaft and mating member.

' A further object of the invention is the provision of a coupling forrotary shafts in which a shaft and a mating sleeve member each areformed with diametrically opposed key ways, with the mating sleevemember mounting in its key ways a U-shaped key member arranged thereinso that the open end of said key member extends toward the end of saidsleeve member and in which means are provided to secure the key memberin the sleeve member to effect a slidable, readily releasable andbacklash free key coupling between the shaft and sleeve member withoutremoval of any key means.

In addition, the invention has other marked superiorities whichradically distinguish it from presently known structures. Theseimprovements embodying certain novel features of construction are moreclearly set forth in the following specification and the appendedclaims, and a preferred embodimentof the invention is hereinafter shownwith reference to the accompanying drawing forming part of thespecification.

In the drawing: I

Fig. 1 is alongitudinal sectional view, partly in e1evation,.through arotary power tool showing a rotary shaft coupling built in accordancewith the invention between the rotor shaft and the tool drive shaft;

Fig. 2 is a cross-sectional view through the rotary shaft coupling shownin Fig. 1, the section being taken on line 2-2 of Fig. 1;

Figs. 3 through 6, show the elements of the rotary shaft coupling, thusFig. 3 is a fragmentary sectional view of the rotor shaft, partly inelevation, showing the arrangement of the key ways in said shaft;

Fig. 4 is a side-view of the split ring holding the key member inthesleeve-like end of the drive shaft;

Fig. 5 is a plan view of the U-shaped key member, and

Fig. 6 is a fragmentary sectional view of the drive shaft, partly inelevation, showing the arrangement of the keyways in the sleeve-like endof said drive shaft.

Referring now more particularly to the exemplified form of the inventionshown in the drawing, reference numeral 2 represents a rotary power toolsimilar in construction to the power tool shown in the parentapplication above referred to. This power tool embodies a handle member3 having a control trigger 4, a central head 5, a cylinder section 8 anda front head I, and carries in its cylinder section a rotor, the shaft 8of which is mounted in a ball bearing 9 at the upper end of front head'I and coupled with a drive shaft I0 rotatably mounted in front head Iby means of ball bearings l l. Drive shaft Ill supports at its lower enda grinding wheel [2 secured thereto, as customary, by inner and outerwheel washers l4 and I5 forced toward each other by a nut member IS.

The coupling between the lower end of rotor shaft 8 and the upper end ofdrive shaft I0 is effected by a U-shaped key member I! embodying two legportions l8, l8 and a half-circular web portion l9 and cooperating withsaid shafts in slidably securing same to each other. For

such purpose the rotor shaft.8 has in its lower end two outer key ways20, 2| diametrically arranged with respect to each other and parallellyof head 22 so that web portion IQ of said key 7 member extendsdiametrically opposite the front face of shaft 8 and permits properadjustment of the two shafts with respect to each other. 1 Key member I!is held in key ways M, 25 of head 22 by means of a spring split ring 26engaging a circular groove 21 in bore 23 and preventing axial movementof said key member in said bore. This arrangement simplifies couplingproceedings, as the end of shaft 8 when rotated to align its key wayswith key member IT can readily and'easily be extended in-to head 22 andeffeot'the desired coupling between the two shafts without actuation ofthe key member.

Having thus described my invention, What I claim is:

1. In a rotary shaft coupling a shaft having diametrically opposed keyways-arranged lengthwise thereof, a mating sleeve sleeved upon saidshaft and having diametrically opposed key ways arranged lengthwise ofsaid sleeve in the inner wall thereof, anda U-shaped key member Withinsaid sleeve having its leg portions partly extended into the key waysofsaid shaft and partly extended into the key ways of said mating sleevefor coupling said shaft to said mating sleeve, said key member havingits web portion intersecting the axes of said shaft and mating sleeve.

2. In a rotary shaft coupling a shaft having diametrically opposed keyways arranged lengthwise thereof, a mating sleeve sleeved upon saidshaft and having diametrically opposed key ways arranged lengthwise ofsaid sleeve in the inner wall thereof, a U-shaped key member couplingsaid shaft to said mating, sleeve; and means securing said key member insaid sleeve member, said key member having its leg portions partlyarranged in said key slots and partly extended therefrom for couplingengagement with said shaft, and said key member having its web portionintersecting the axes of said shaft and mating sleeve.

3. ma rotary shaft coupling a shaft having diametrically opposed keyways arranged lengthwise thereof, a second shaft having an enlargedhead, a bore in said head fitting said first shaft, diametricallyopposed key ways in the wall of said bore, a U-shaped key member in saidbore having its leg portions extended into the key ways of said bore andshaft to couple said shafts without backlash and having its web portionintersecting the axis of said bore opposite the end of said shaft topermit-axial adjustments of said shafts, and means to look said U-shapedkey-member in said bore without interfering with axial adjustment ofSaid shaftswith respect to eachother.

4. A rotary shaft coupling as described in claim 3, wherein the meanslooking the U shaped key member consists of a split-ring seated in acircular recess in the wall ofsaid bore near the end of said head.

CHARLES F. OVERLY.

